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support full-screen? Yes. Chrome/Opera No. Firefox/ Samsung Internet Not yet Yes Yes
cannot work on some mobile browser that don't understand JavaScript such as.....
cannot work on Internet Explorer 9 and below



This email address is being protected from spambots. You need JavaScript enabled to view it.; Fu-Kwun Hwang

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Quick Survey for HCI Lessons for 3 simulations



Non-linear motion


Play with the 2 Cannon pointing at each model. This simulation can be used to illustrate the thought experiment "The Monkey and the Hunter" often used to illustrate the effect of gravity on projectile motion.

The Monkey and the Hunter Experiment

A hunter with a blowgun goes out in the woods to hunt for monkeys and sees one hanging in a tree, at the same level as the hunter's head. The monkey, we suppose, releases its grip the instant the hunter fires his blowgun. Where should the hunter aim and when should he fire in order to hit the monkey?


Do you know why the cannonball always hit each other provided they point at each other and velocities are pointed towards each other and greater than zero?

Answer :

is conceptually in the green line being without the effects of gravity, the cannons ball will meet as predicted by Newton's 1st Law of motion without net external force.
now, adding the same gravitational acceleration means both cannon balls will move down at the same rate ( pink lines).
therefore, the 2 cannon balls has to collide .


  1. ejss_model_kinematics CT_kinematics (1017).ppt 
  2. ejss_model_kinematics Motion in One Dimension student worksheet (2017).docx
  3. Motion in One Dimension student worksheet (dl-gwf) Link1, Link2  by Lyna, Gavin, Dave and lookang 

Sample Learning Goals

(g) solve problems using equations which represent uniformly accelerated motion in a straight line, including the motion of bodies falling in a uniform gravitational field without air resistance


  1.  MIT Physics Demo -- Monkey and a Gun by mittechtv 
  2.  Monkey and Hunter Apparatus Demonstration by The Amazing Cenco Physics Presents
  3. Demo by Alom Shaha from National STEM Centre
  4. by University of Minnesota


  1. by Loo Kang Wee
  2. original by Fu-Kwun Kwang
  3. another copy by Fu-Kwun Kwang in OSP

Other Simulations

  1. by The Physics Classroom
  2. Projectile Motion: Tranquilize the Monkey GeoGeBra by ukukuku
  3. Flash simulation
  4. Java simulation

Project related:

    1. Understanding Teacher Learning Community as Support for Implementation of Open Source Physics for Conceptual Instruction Project Number: OER 10/15 GWF Project Duration: 01 July 2015 - 30 April 2017

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